In the red key room, climb the crates in the northeast corner and make jumps to the crates westward, eventually winding up on the crate with the berserk pack. (sector 21)

Open the red door and look south, opening the wall here to reach the courtyard. There is a soul sphere to grab here. (sector 60)

From Secret #1, look south, and jump to the tiny crate and then across to the southwest corner. Lean on the south side and press on the brown crate to open it, revealing a switch. After flipping it, return to the starting room and the large outdoor area to the south will be available. (sector 195)